Updated App Store Review Guidelines published this week include a variety of changes, most notably dictating that apps wanting to make use of Face ID on the iPhone X must offer an "alternate authentication method" for children under 13.
Given the lack of Touch ID on the phone, and the demands of Apple's LocalAuthentication framework, that would translate into a passcode or passphrase. It's uncertain why Apple is making the stipulation, since Face ID content isn't uploaded to the cloud and should be safely secured on-device as well.
The company is likely trying to allay any fears from parents, as well as deal with a fundamental limitation of Face ID. The technology will support only one person per device, which would mean parents sharing an iPhone X would always have to unlock apps themselves if they relied too heavily on facial recognition.
Other tweaks to the Guidelines include provisions against antivirus apps -- which simply don't work on iOS -- as well as a ban on simple ARKit apps like technology demos. ARKit apps must include "rich and integrated augmented reality experiences," Apple says.
The company has meanwhile softened its tipping policy, allowing person-to-person financial gifts that bypass the App Store's in-app purchase system. Apple normally claims a 30 percent cut from in-app transactions, and indeed the new rules say that app creators can't claim any money from gifts either. The changes are presumably a reaction to the popularity of tipping in Chinese apps, which resulted in a brief crackdown earlier this year, followed by a half-step measure in which tips were possible as in-app purchases.